{{Short description|Species of lichen}} {{Use US English|date=March 2023}} {{Use dmy dates|date=March 2023}} {{Speciesbox | image = | image_caption = | status = G2 | status_system = TNC | status_ref = <ref name=NS>{{cite NatureServe |id=2.785280 |title=''Gyalectidium floridense'' |access-date=12 June 2025}}</ref> | taxon = Gyalectidium floridense | authority = Safranek & [[Robert Lücking|Lücking]] (2005) }}

'''''Gyalectidium floridense''''' is a species of [[foliicolous lichen|foliicolous]] (leaf-dwelling), [[crustose lichen]] in the family [[Gomphillaceae]].<ref name="CoL"/> It is found in the southeastern United States, where it grows on the leaves of ''[[Citrus]]'' and [[sabal|palmetto]].

==Taxonomy==

It was [[species description|formally described]] as a new species in 2005 by William Safranek and [[Robert Lücking]]. The [[type (biology)|type specimen]] was collected by the first author from a residential property in [[Brevard County, Florida]], where it was found growing on the leaves of ''[[Citrus]]''.<ref name="Safranek & Lücking 2005"/> It has also been recorded in [[Louisiana]] growing on [[sabal|palmetto]] leaves.<ref name="Lücking et al. 2007"/>

''Gyalectidium floridense'' is in the ''[[Gyalectidium areolatum]]'' [[species group]], which is in ''[[Gyalectidium]]'' section ''Areolectidium'' [[series (botany)|series]] ''Areolate''. The primary characteristic of this particular group of species is the presence of a crystalline thallus; [[calcium oxalate]] crystals congregate and form large {{lichengloss|areoles}} on the patches of the thallus.<ref name="Safranek & Lücking 2005"/> Other eastern North American species with this thallus characteristic are ''[[Gyalectidium tuckerae|G.&nbsp;tuckerae]]'' and ''[[Gyalectidium appendiculatum|G.&nbsp;appendiculatum]]''.<ref name="Lücking et al. 2007"/>

==Description==

The thallus of ''Gyalectidium floridense'' can be found on the surface of leaves, either on top ({{lichengloss|epiphyllous}} or underneath ({{lichengloss|hypophyllous}}, and is crustose in nature. The thallus is made up of small, rounded to irregular patches that are 0.8–1.5&nbsp;mm in diameter and 20&nbsp;[[micrometre|μm]] thick. It has a cartilaginous, corticiform layer and appears greenish in color. The {{lichengloss|areoles}}, which are 0.4–0.8&nbsp;mm in diameter, are encrusted with [[calcium oxalate]] crystals, making them silvery gray in color. [[Apothecia]] are not present in this species.<ref name="Safranek & Lücking 2005"/>

{{lichengloss|Hyphophores}} (highly derived [[conidiomata]] that are unique to the family Gomphillaceae), which are frequently found near the thallus margin along the edges of the areoles, are also present. They have scales that project vertically and appear horn-shaped when folded along their vertical axis. The hyphophores are 0.4–0.6&nbsp;mm long and 70–90&nbsp;μm wide when folded and are grayish to whitish in color.<ref name="Safranek & Lücking 2005"/>

The {{lichengloss|photobiont}} in ''Gyalectidium floridense'' is {{lichengloss|chlorococcoid}}, with cells that are 8–12&nbsp;μm in diameter. The {{lichengloss|diahyphae}} in this lichen are branched throughout and {{lichengloss|moniliform}} in shape. The segments of the diahyphae are sausage-shaped, measuring 4–8 by 2–3&nbsp;μm in size, and are colorless. Scattered [[alga]]l cells that are 4–6&nbsp;μm in diameter are also present.<ref name="Safranek & Lücking 2005"/>

The structural organization of the cystalline deposits and the thallus in this species has been examined using [[scanning electron microscopy]]. Clear continuity can be observed between the epilayer of the thallus in ''Gyalectidium floridense'' and the prothallus. Spaces, which may be occupied by crystalline deposits, are frequently visible between the epilayer and the remaining lower part of the thallus. In certain areas, the epilayer may exhibit discontinuities, especially in regions where it is raised by the purported crystal deposits located below.<ref name="Sanders et al. 2016"/>

===Similar species===

''Gyalectidium floridense'' bears some resemblance to specific forms of ''[[Gyalectidium catenulatum|G.&nbsp;catenulatum]]'', which occurs in northern areas of Argentina. This particular species also features enrolled hyphophores, with similar horn-like shapes found in the populations from northern Argentina. However, the flattened-out hyphophores in ''G.&nbsp;catenulatum'' possess parallel sides with acute projections at their edges. Also, ''G.&nbsp;catenulatum differs'' from ''G.&nbsp;floridense'' in that its smooth thallus is not encrusted with crystals.<ref name="Safranek & Lücking 2005"/>

''[[Gyalectidium plicatum]]'', found in Chile and Mexico, appears to be the species that is most closely related to ''Gyalectidium floridense''. While there are similarities between the two species, the hyphophores of ''G.&nbsp;plicatum'' are more irregularly folded, oblique, and submarginal in nature. The areoles of ''G.&nbsp;plicatum'' are also thicker and appear whitish in color, with the dominance of these crystalline structures covering most of the thallus.<ref name="Safranek & Lücking 2005"/>

==References== {{Reflist|refs=

<ref name="CoL">{{Catalogue of Life |id=6L79X |title=''Gyalectidium floridense'' Safranek & Lücking |access-date=30 March 2023}}</ref>

<ref name="Lücking et al. 2007">{{cite journal |last1=Lücking |first1=Robert |last2=Buck |first2=William R. |last3=Plata |first3=Eimy Rivas |title=The lichen family Gomphillaceae (Ostropales) in eastern North America, with notes on hyphophore development in ''Gomphillus'' and ''Gyalideopsis'' |journal=The Bryologist |volume=110 |issue=4 |year=2007 |doi=10.1639/0007-2745(2007)110[622:tlfgoi]2.0.co;2 |pages=622–672}}</ref>

<ref name="Safranek & Lücking 2005">{{cite journal |last1=Safranek |first1=William W. |last2=Lücking |first2=Robert |title=''Gyalectidium floridense'', a new foliicolous lichen from the Southeastern United States |journal=The Bryologist |volume=108 |issue=2 |year=2005 |doi=10.1639/0007-2745(2005)108[0295:GFANFL]2.0.CO;2 |pages=295–297 |s2cid=85590834}}</ref>

<ref name="Sanders et al. 2016">{{cite journal |last1=Sanders |first1=William B. |last2=De Los Ríos |first2=Asunción |title=Structure of foliicolous thalli of the Gomphillaceae in a south-western Florida lichen community |journal=The Lichenologist |volume=48 |issue=4 |year=2016 |doi=10.1017/s0024282916000219 |pages=293–303}}</ref>

}}

{{Taxonbar|from=Q17388099}}

[[Category:Gyalectidium|floridense]] [[Category:Lichen species]] [[Category:Lichens described in 2005]] [[Category:Lichens of the Southeastern United States]] [[Category:Taxa named by Robert Lücking]]